In red cells from patients with sickle cell anemia, hemoglobin S denatures and forms Heinz bodies. Binding of Heinz bodies to the inner surface of the sickle cell membrane promotes clustering and colocalization of the membrane protein band 3, outer surface-bound autologous IgG and, to some extent, the membrane proteins glycophorin and ankyrin. Loss of transbilayer lipid asymmetry is also found ...

Figure 1: Membrane lipids are polar and can be separated into phospholipids and glycolipids, for which the basic structures are shown. Note the difference in the third binding site. Phospholipids have a phosphate bound to an alcohol (glycerol-) or choline (sphingo-), while glycolipids have a sugar group. Source: Lafer, Eileen. “Membrane Lipids I and II: Glycerophospholipids and Sphingolipids.” ...

Plasmodesmata (PD) are nano-sized membrane-lined channels controlling intercellular communication in plants. Although progress has been made in identifying PD proteins, the role played by major membrane constituents, such as the lipids, in defining specialized membrane domains in PD remains unknown. Through a rigorous isolation of "native" PD membrane fractions and comparative mass spectrometry...

Our understanding of membranes and membrane lipid function has lagged far behind that of nucleic acids and proteins, largely because it is difficult to manipulate cellular membrane lipid composition. To help solve this problem, we show that methyl-α-cyclodextrin (MαCD)-catalyzed lipid exchange can be used to maximally replace the sphingolipids and phospholipids in the outer leaflet of the plasm...

In multicellular organisms, cells communicate with each other via extracellular molecules such as nucleotides, lipids, short peptides, or proteins. These molecules are released in the extracellular space to bind to receptors on other cells, thus modifying intracellular signaling in the recipient cells. In addition to these single molecules, cells also release in their extracellular environment ...

Viruses intricately interact with and modulate cellular membranes at several stages of their replication, but much less is known about the role of viral lipids compared to proteins and nucleic acids. All animal viruses have to cross membranes for cell entry and exit, which occurs by membrane fusion (in enveloped viruses), by transient local disruption of membrane integrity, or by cell lysis. Fu...

Erythrocytes from normal subjects and from cases of sickle cell disease were exposed to hydrogen peroxide and the extent of membrane lipid peroxidation studied. Significantly increased peroxidation was observed in intact erythrocytes, isolated lipids from intact erythrocytes or their ghosts compared with normal controls. However, the extent of lipid peroxidation was less for isolated lipids of ...

Introduction of selectively chemical reactive groups at the cell surface enables site-specific cell surface labeling and modification opportunity, thus facilitating the capability to study the cell surface molecular structure and function and the molecular mechanism it underlies. Further, it offers the opportunity to change or improve a cell's functionality for interest of choice. In this study...

Cell membranes are composed of many different lipids and protein receptors, which are important for regulating intracellular functions and cell signaling. To orchestrate these activities, the cell membrane is compartmentalized into microdomains that are stably or transiently formed. These compartments are called "lipid rafts". In gamete cells that lack gene transcription, distribution of lipids...

Ethylene and abscisic acid (ABA) both accelerate senescence of detached Arabidopsis leaves. We previously showed that suppression of Phospholipase Dδ (PLDδ) retarded ABA-promoted senescence. Here, we report that ethylene-promoted senescence is retarded in detached leaves lacking PLDδ. We further used lipidomics to comparatively profile the molecular species of membrane lipids between wild-type ...